In recent years, the popularity of digital cellular communication systems has been phenomenal. Today, digital cellular subscribers number in the millions throughout the world. The growth of the digital cellular market has fuelled research into novel services for use by subscribers, including caller ID, fax messaging, voice mail, call waiting, call forwarding and conference calls. The newest generation of digital cellular communication systems, PCS, introduced a range of features and services surpassing those previously available including include sleep mode, short message service (SMS), increased resistance to eavesdropping, text dispatch service, etc.
SMS, which first appeared in the early 1990s in Europe, provides a mechanism for transmitting short messages to and from digital cellular handsets. A Short Message Service Center (SMSC) is used to store and forward short messages to PCS digital cellular handsets. The digital cellular telecommunications network is used to transport the messages between the SMSC and the digital cellular handsets. A digital cellular handset that is active can receive or transmit a short message at any time, regardless of whether a voice or data call is in progress. SMS is characterized by out-of-band packet delivery and low-bandwidth message transfer.
At the same time as digital cellular communications have gained in popularity, the Internet itself has grown to be considered as an alternative voice communication tool. In recent years there have been many advancements and developments in the area of Internet telephony, which refers to communication services e.g. voice, facsimile, and/or voice-messaging applications that are transported via the Internet, rather than the Public Switched Telephone Network (PSTN). Telephone subscribers are drawn to Internet telephony as an alternative to traditional forms of communications, especially for long-distance telephone calls, because it offers tremendous cost savings relative to the PSTN. With the use of Internet telephony, subscribers can bypass long-distance carriers and their per-minute usage rates and run their voice traffic over the Internet for a flat monthly Internet access fee.
Due to the complexity of both the digital cellular telecommunications systems and the hardware and software requirements of Internet telephony, there are no prior art systems that marry the flexibility of digital cellular communications systems with the cost savings of Internet telephony. Since digital cellular handsets have no fixed location, call set-up, initiation and establishment are particularly difficult to accomplish in the Internet domain.
Consequently, a need has developed to provide a system for providing a digital cellular handset that is enabled for Internet telephony. Still further, a need has developed to provide a means for setting up, initiating and establishing a digital cellular telephone call over the Internet.